Computer-Aided Design of a Novel Poly-Epitope Protein in Fusion with an Adjuvant as a Vaccine Candidate Against Leptospirosis

Background: Leptospirosis is a prevalent zoonotic disease caused by Leptospira interrogans bacterium. Despite the importance of this disease, traditional strategies including attenuated and inactivated vaccines have not been able to prevent leptospirosis. Objective: Hence, this study was designed to develop a novel poly-epitope fusion protein vaccine against Leptospirosis. Methods: To do so, the best epitopes of OmpA, LipL45, OmpL1, LipL41 and LipL21 proteins were predicted. Then, the best-predicted epitopes were applied to assemble IFN-γ, MHC I binding, B cell and MHC II binding fragments, and heparin-binding hemagglutinin adhesion was used as a molecular adjuvant. After designing the vaccine, the most important features of it, including physicochemical parameters, protein structures and protein-protein interaction, were evaluated. Finally, the nucleotide sequence of the designed vaccine was used for codon adaptation. Results: The results showed that the designed vaccine was a stable protein with antigenicity of 0.913, which could dock to its receptor. The results also suggested that the nucleotide sequence of the designed vaccine could be expressed in the prokaryotic system. Conclusion: Based on the results of this study, it can be concluded that the vaccine can be a promising candidate to control Leptospirosis.